Marine-vessel transmission

ABSTRACT

The invention relates to a marine-vessel transmission having an input-drive shaft ( 10 ), which extends along an input-drive shaft axis (A) and on which an input-drive shaft gearwheel ( 12 ) is arranged, a first pinion shaft ( 14 ), which extends coaxially with respect to the input-drive shaft ( 10 ) and on which a first pinion ( 16 ) is arranged, a second pinion shaft ( 24 ), which extends parallel to the input-drive shaft ( 10 ) and on which a pinion shaft gearwheel ( 28 ), which engages with the input-drive shaft gearwheel ( 12 ), and a second pinion ( 26 ) are arranged, an intermediate shaft ( 18 ), on which a spur gear ( 20 ), which engages with the first pinion ( 16 ) and the second pinion ( 26 ), and a bevel pinion ( 22 ) are arranged, and an output-drive shaft ( 30 ), which extends along an output-drive shaft axis (P) which runs at an angle (α) of more than 75° with respect to the input-drive shaft axis (A), and on which a spur bevel gear ( 31 ) is arranged, which forms a bevel drive with the bevel pinion ( 22 ).

This application claims priority to and the benefit of Patent Application DE 10 2008 018 703.8 filed in Germany on Apr. 10, 2008, which is incorporated herein by reference.

BACKGROUND AND SUMMARY OF THE DISCLOSURE

The invention relates to a marine-vessel transmission, for example for a yacht.

A physically short marine-vessel transmission is known from EP 1 464 574 A2. Marine-vessel transmissions such as these are used, for example, in order to transmit the torque from an engine to a pod drive in yachts. In order that the drive unit comprising the motor and transmission occupies as little space as possible, physically short transmissions are used. The known marine-vessel transmission has the disadvantage that it is still physically relatively long. A further disadvantage is that the transmission is not suitable as a platform, that is to say a new transmission must be designed for each stepping down of an engine rotation speed to a propeller rotation speed, and this is complex.

US 2008/0026652 A1 discloses a marine-vessel transmission by means of which the rotation speed of the engine can be increased when the boat in which the transmission is installed is traveling at high speed. A transmission such as this has the disadvantage that it is not very compact.

DE 30 15 473 C2 discloses a stern drive for boats, which can be particularly compact. This has the disadvantage that increased production effort must be conducted because of the large number of gearwheels with inclined teeth.

US 2007/0180941 A1 discloses a marine-vessel transmission which allows two speeds. This also has the disadvantage that a plurality of bevel gears must be provided, thus increasing the production effort.

The invention is based on the object of specifying a marine-vessel transmission which is physically particularly short and is suitable for pod drives.

The invention solves the problem by means of a marine-vessel transmission as claimed in claim 1.

This marine-vessel transmission has the advantage that it can easily be converted for a different step-down ratio. All that is necessary to do so is to change the diameter of the first pinion and second pinion on the one hand, and the spur gear on the other hand.

A further advantage is the ease of adjustment of the bevel-gear drive since, in comparison to the prior art, only one pair comprising a bevel pinion and a spur bevel gear need be adjusted relative to one another.

A further advantage is that the marine-vessel transmission according to the invention is physically particularly compact. A large amount of useful space therefore remains when the marine-vessel transmission is installed, for example, in a yacht.

Furthermore, the marine-vessel transmission can advantageously be maintained easily. The horizontal axis offset of the marine-vessel transmission can also easily be varied in the course of redesign, which means that the marine-vessel transmission can be matched to the respective marine-vessel design, for example a yacht, with little effort.

Another advantage is that the marine-vessel transmission is physically particularly light in weight. This is because the second pinion shaft can be designed to be particularly light in weight. This is because of the fact that, when the marine-vessel transmission is used in a yacht, only a small drive torque need be transmitted when traveling astern. In consequence, while the input-drive shaft and the first pinion shaft must be designed to transmit the torque which is necessary for traveling at high speed forwards, the second pinion shaft can be produced to be light in weight.

Furthermore, the marine-vessel transmission according to the invention has the advantage of high step-up ratio variability in the same physical space. In other words, the step-up ratio can easily be changed by varying the diameter of individual pinions. A further advantage is the simple capability to design a hybrid drive. For example, the input-drive shaft can be connected to a diesel engine, and an electric motor is coupled to a torque introduction journal. Low-noise and low-emission operation are therefore possible.

The input-drive shaft according to one preferred embodiment has a shaft stub for connection to a motor, with the spur bevel gear being arranged on the same side as the shaft stub with respect to a plane through the first pinion, the second pinion and the spur gear. This makes it possible to keep the distance between the motor on the one hand and a marine-vessel propeller, which is arranged on the output-drive side of the transmission, on the other hand particularly small. Particularly in the case of yachts, it is often desirable for safety reasons for the marine-vessel propeller to be at a certain distance from the stern. In the case of conventional transmissions, this leads to a loss of useful space in the yacht.

It is preferable for the marine-vessel transmission to be designed such that the first and the second pinion are always each engaged with the spur gear, and such that the input-drive shaft gearwheel is always engaged with the pinion shaft gearwheel. Furthermore, the bevel pinion and the spur bevel gear are always engaged with one another.

A switchable input-drive shaft clutch is preferably arranged on the input-drive shaft, by means of which the input-drive shaft gearwheel can be connected to the first pinion shaft such that they rotate together. Furthermore, a switchable pinion shaft clutch is preferably arranged on the second pinion shaft, by means of which the pinion shaft gearwheel can be connected to the second pinion shaft such that they rotate together. The direction of rotation of the output-drive shaft can be reversed by means of the input-drive shaft clutch and the pinion shaft clutch.

The switchable input-drive shaft clutch is preferably in the form of a hydraulically switchable disk clutch. Disk clutches such as these are particularly highly suitable for transmission of high torques and high powers.

A particularly compact design is achieved if the input-drive shaft gearwheel is in the form of a housing with an external tooth system of the disk clutch. In other words, the input-drive shaft gearwheel preferably radially completely surrounds the input-drive shaft clutch. It is advantageous for the housing to at least partially axially surround the disk clutch. This means that a projection of the input-drive shaft gearwheel onto the input-drive shaft is at least partially coincident with the projection of the disk clutch onto the input-drive shaft. The input-drive shaft gearwheel preferably axially completely surrounds the input-drive shaft clutch, such that the projection of the input-drive shaft gearwheel onto the input-drive shaft encloses the projection of the disk clutch onto the input-drive shaft.

According to one preferred embodiment, the switchable pinion shaft clutch is also a hydraulically switchable disk clutch. It is also advantageous for the pinion shaft gearwheel to be in the form of a housing with an external gear system, of the pinion shaft clutch. In other words, the pinion shaft gearwheel radially completely surrounds the pinion shaft clutch, and at least partially surrounds it axially, in particular completely axially. This also results in a particularly compact marine-vessel transmission.

It is preferable for the marine-vessel transmission to be designed such that the first and the second pinion are each always engaged with the spur gear, and such that the input-drive shaft gearwheel is always engaged with the pinion shaft gearwheel. Furthermore, the bevel pinion and the spur bevel gear are always engaged with one another.

A switchable drive shaft clutch is preferably arranged on the input-drive shaft, by means of which the input-drive shaft gearwheel can be connected to the first pinion shaft such that they rotate together. Furthermore, a switchable pinion shaft clutch is preferably arranged on the second pinion shaft, by means of which the pinion shaft gearwheel can be connected to the second pinion shaft such that they rotate together. The rotation direction of the output-drive shaft can be reversed by means of the input-drive shaft clutch and the pinion shaft clutch.

The switchable input-drive shaft clutch is preferably in the form of a hydraulically switchable disk clutch. Disk clutches such as these are particularly highly suitable for the transmission of high torques and high powers.

A particularly compact design is achieved if the input-drive shaft gearwheel is in the form of a housing with an external tooth system of the disk clutch. In other words, the input-drive shaft gearwheel preferably radially completely surrounds the input-drive shaft clutch. It is advantageous for the housing to at least partially axially surround the disk clutch. This means that a projection of the input-drive shaft gearwheel onto the input-drive shaft is at least partially coincident with the projection of the disk clutch onto the input-drive shaft. The input-drive shaft gearwheel preferably axially completely surrounds the input-drive shaft clutch, such that the projection of the input-drive shaft gearwheel onto the input-drive shaft encloses the projection of the disk clutch onto the input-drive shaft.

According to one preferred embodiment, the switchable pinion shaft clutch is also a hydraulically switchable disk clutch. It is also advantageous for the pinion shaft gearwheel to be in the form of a housing with an external gear system, of the pinion shaft clutch. In other words, the pinion shaft gearwheel radially completely surrounds the pinion shaft clutch, and at least partially surrounds it axially, in particular completely axially. This also results in a particularly compact marine-vessel transmission.

An electrical drive unit is preferably provided in order to switch the input-drive shaft clutch and the pinion shaft clutch, and is designed in order to switch the input-drive shaft clutch and the pinion shaft clutch such that at most one of the two clutches is always connected to the respective shaft such that they rotate together. This results in the output-drive shaft either rotating in the same direction as the input-drive, in the opposite direction to the input-drive, or not at all.

In one preferred embodiment, the marine-vessel transmission has a torque tap-off journal for tapping off a torque at a point which is not the same as the output-drive shaft. A tap-off journal such as this is also known as a PTO (Power Take Off). The marine-vessel transmission according to the invention is particularly highly suitable for the provision of a torque tap-off journal since three shafts are available on which these tap-off journals can be fitted. It is also possible to provide a further shaft on which the torque tap-off journal is provided.

In the preferred embodiment, the marine-vessel transmission furthermore has a torque introduction journal for introduction of an input-drive torque. A torque introduction journal such as this is also known as a PTI (Power Take In). When an input-drive torque such as this is being introduced from some appliance other than the motor which drives the input-drive shaft, then the input-drive shaft clutch and the pinion shaft clutch are disengaged. If an electrical drive unit exists, then this is designed in order to disengage both clutches when it is intended to introduce the external input-drive torque.

The marine-vessel transmission is particularly preferably designed such that the input-drive shaft axis runs essentially horizontally when the marine-vessel transmission is in the installed position. The feature that the input-drive axis runs essentially horizontally means in particular that it is possible, but not necessary, for the input-drive shaft axis to run horizontally in the strictly mathematical and physical sense. Minor discrepancies from the horizontal position, for example of less than 10°, and in particular of less than 5°, can be tolerated. This has the advantage that this allows hydraulically switchable disk clutches to be operated in a particularly operationally reliable manner.

It is particularly advantageous for the marine-vessel transmission to be designed to transmit a mechanical power of more than 430 kW, in particular of more than 1300 kW. Marine-vessel transmissions such as these are designed to be connected permanently to a marine vessel, in particular a yacht, and, for example, are not outboard motors.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in more detail in the following text with reference to one exemplary embodiment. In this case, in the figures:

FIG. 1 a shows a perspective view of a marine-vessel transmission according to the invention, in which the housing has been cut away,

FIG. 1 b shows the marine-vessel transmission as shown in FIG. 1 a, in the form of a further illustration,

FIG. 2 shows a view of one end of the marine-vessel transmission as shown in FIG. 1,

FIG. 3 shows a section through the marine-vessel transmission along the line F-F shown in FIG. 2, and

FIG. 4 shows a section through the marine-vessel transmission along the line G-G shown in FIG. 2.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 a shows a marine-vessel transmission with an input-drive shaft 10 which is designed to be connected to a motor, which is not shown. The input-drive shaft 10 extends along an input-drive shaft axis A and is fitted with an input-drive shaft gearwheel 12. FIG. 1 a shows the input-drive shaft gearwheel 12 without its external tooth system, while this external tooth system can be seen in FIG. 1 b.

The input-drive shaft 10 is designed to be connected at a shaft stub 11 to a marine-vessel motor.

A first pinion shaft 14 runs coaxially with respect to the input-drive shaft 12 and thus likewise extends along the input-drive shaft axis A. A first pinion 16 is provided on the first pinion shaft 14. By way of example, the first pinion 16 is an integral component of the first pinion shaft 14.

An intermediate shaft 18 is arranged obliquely underneath the first pinion shaft 14 in the installed position, and a spur gear 20 is arranged on it. By way of example, the spur gear 20 is an integral component of the intermediate shaft 18. The intermediate shaft 18 furthermore has a bevel pinion 22 whose tooth system, in the same way as a tooth system on the spur gear 20, is not shown in FIG. 1 a, but is actually shown in FIG. 1 b. The bevel pinion 22 may also be an integral component of the intermediate shaft 18. The intermediate shaft 18 extends along an intermediate shaft axis Z, which runs parallel to the input-drive shaft axis A and has a vertical axis offset V from it. There is a preferably horizontal axis offset H between the first pinion shaft 14 and the second pinion shaft 24.

A second pinion shaft 24 is arranged alongside the drive shaft 10 and the first pinion shaft 14, preferably at the same level as the installed position, and extends along a second pinion shaft axis parallel to the input-drive shaft axis A. A second pinion 26 is arranged on the second pinion shaft 24, which second pinion 26 may be an integral component of the second pinion shaft 24, and is shown without its external tooth system in FIG. 1 a.

In the same way as the first pinion 16, the second pinion 26 is always engaged with the spur gear. A pinion shaft gearwheel 28 is arranged adjacent to the input-drive shaft gearwheel 12 on the second pinion shaft 24 and, in the embodiment shown in FIG. 1, is in the form of a housing, with external tooth system, of a disk clutch which will be described further below.

An output-drive shaft 30 which extends along an output-drive shaft axis P is located underneath the intermediate shaft axis Z in the installed position. The output-drive shaft axis P runs essentially at right angles to the intermediate shaft axis Z, that is to say an output-drive shaft axis angle α is essentially 90° and, for example, is between 85 and 95°. The output-drive shaft axis P therefore runs essentially vertically in the installed position.

A spur bevel gear 31 is arranged on the output-drive shaft 30 and can represent an integral component of the output-drive shaft 30. Alternatively, the spur bevel gear 31 is attached to the output-drive shaft 30 via a shaft and hub connection. The spur bevel gear 31 is shown without its tooth system in FIG. 1 a and with its tooth system in FIG. 1 b, and is always engaged with the bevel pinion 22. The bevel pinion 22 and the spur bevel gear 31 therefore form a bevel drive.

FIG. 2 shows the marine-vessel transmission 32 with a housing 34 in which the components are arranged as shown in FIGS. 1 a and 1 b. The output-drive shaft 30 leaves the housing 34 on a lower face 36. The intermediate shaft 18 is borne in intermediate shaft bearings 38, the first pinion shaft 14 is borne in first pinion shaft bearings 40, and the second pinion shaft 24 is borne in second pinion shaft bearings 42, and closure covers for the individual bearings can in each case be seen in FIG. 2.

The housing 34 comprises a transmission foot 44 which runs essentially horizontally when the housing 34 and therefore the marine-vessel transmission 32 are in the installed position, and is designed for installation of the marine-vessel transmission 32 in a marine vessel, for example a yacht.

FIG. 3 shows a section along the line F-F as shown in FIG. 2. FIG. 3 shows an external tooth system 46 of the first pinion 16, which engages with an external tooth system of the spur gear 20. The figure also shows that the input-drive shaft gearwheel 12 is formed by a clutch housing with an external tooth system 48 which surrounds an input-drive shaft clutch 50.

The input-drive shaft clutch 50 is a hydraulic disk clutch and comprises a multiplicity of first disks 52.1, which are connected to the input-drive shaft gearwheel 12 and thus to the input-drive shaft 10 such that they rotate together, and second disks 52.2, which are rotationally rigidly connected to the first pinion shaft 14. The disks 52.1, 52.2 can be brought into frictional contact with one another via a hydraulic cylinder 54 such that the input-drive shaft 10 is coupled to the first pinion shaft 14. In the situation illustrated in FIG. 3, the hydraulic cylinder 54 does not push the first disks 52.1 and the second disks 52.2 together, which results in the first pinion shaft 14 being decoupled from the input-drive shaft 10.

If, for example, the input-drive shaft 10 is rotating at a rotation speed ω₁ (cf. FIG. 1 a) about the input-drive shaft axis A and the input-drive shaft clutch 50 is closed, then the first pinion shaft 14 also rotates at the rotation speed ω₁. The intermediate shaft 18 therefore rotates at a rotation speed ω₂ which is less than the rotation speed ω₁. The transmission ratio ω₁/ω₂ is, for example, 1.5 to 2.5, in particular 2. This means that the first pinion 16 has half as many teeth as the spur gear 20.

The bevel gear 22 transmits the rotary movement to the spur bevel gear 31, such that the output-drive shaft 30 rotates at a rotation speed ω₃. The tooth systems of the bevel pinion 22 and spur bevel gear 31, which were omitted in FIG. 1 a, can be seen in FIG. 1 b.

FIG. 4 shows a section along G-G as shown in FIG. 2. As can be seen, the second pinion shaft 24 can be connected to the pinion shaft gearwheel 28 via a pinion clutch 56, with the pinion shaft gearwheel 28 being formed by a housing with an external tooth system 58, which accommodates the pinion shaft clutch 56. The pinion shaft clutch 56 is constructed in the same way as the input-drive shaft clutch and has first disks 60.1 which are connected to the pinion shaft gearwheel 28 and second disks 60.2 which are connected to the second pinion shaft 24. The first disks 60.1 and the second disks 60.2 can be brought into contact via a second hydraulic cylinder 62 such that the pinion shaft gearwheel 28 is connected to the second pinion shaft such that they rotate together.

When, as described above in conjunction with FIG. 3, the input-drive shaft clutch 50 is closed, the input-drive shaft 10 and the first pinion shaft 14 rotate at the rotation speed ω₁ (see FIG. 1 a), and the spur gear 20 drives the second pinion 26 which then likewise rotates at the rotation speed ω₁ in the same direction as the first pinion 16, since the two pinions 16, 26 are designed to be identical. The pinion shaft gearwheel 28 engages with the input-drive shaft gearwheel 12, as a result of which it rotates at the rotation speed −ω₁. The pinion shaft clutch 56 is open, as a result of which the pinion shaft gearwheel 28 and the second pinion 26 can rotate in opposite senses.

In order to select this state, an electrical and/or pneumatic drive unit which may have open-loop and/or closed-loop control functions, that is not shown, drives the first hydraulic cylinder 54 (FIG. 3) such that it closes the input-drive shaft clutch 50. At the same time, the drive unit drives the second hydraulic cylinder 62 such that it opens the pinion shaft clutch 56.

In order to switch to idle, the drive unit drives both hydraulic cylinders 54 (FIG. 3) and 62 (FIG. 4) such that the respective hydraulic disk clutches are open. In this case, none of the shafts rotate, with the exception of the input-drive shaft 10.

In order to reverse the rotation direction of the output-drive shaft 30, the drive unit drives a first hydraulic cylinder 54 such that the input-drive shaft clutch 50 is opened. The output-drive shaft gearwheel 12 (FIG. 1 a) then still rotates at the rotation speed ω₁. Furthermore, the drive unit drives the second hydraulic cylinder 62 (FIG. 4) such that the pinion shaft gearwheel 28 is connected to the second pinion shaft 24 such that they rotate together. The second pinion 26 therefore now rotates at the rotation speed −ω₁. In consequence, the spur gear 20 also rotates at the rotation speed −ω₂, as a result of which the spur bevel gear 31 and therefore the output-drive shaft 30 rotate at the rotation speed −ω₃.

When installed in a marine vessel, the output-drive shaft 30 is connected to at least one propeller of a pod drive. The described reversal process reverses the thrust of the propeller. A marine vessel according to the invention has a marine-vessel transmission 32 which, for example, is installed such that the input-drive shaft axis A and therefore also the intermediate shaft axis Z run essentially horizontally. The output-drive shaft 30 then runs essentially vertically to a pod. A reversing transmission is provided in the pod and drives at least one propeller about a propeller axis which runs essentially parallel to the input-drive shaft axis A, or forms an angle of a few degrees with it, for example of less than 15°.

LIST OF REFERENCE SYMBOLS

-   10 Input-drive shaft -   12 Input-drive shaft gearwheel -   14 First pinion shaft -   16 First pinion -   18 Intermediate shaft -   20 Spur gear -   22 Bevel pinion -   24 Second pinion shaft -   26 Second pinion -   28 Pinion shaft gearwheel -   30 Output-drive shaft -   31 Spur bevel gear -   32 Marine-vessel transmission -   34 Housing -   36 Lower face -   38 Intermediate shaft bearing -   40 First pinion shaft bearing -   42 Second pinion shaft bearing -   44 Transmission foot -   46 External tooth system -   48 External tooth system -   50 Input-drive shaft clutch -   52 Disks -   54 Hydraulic cylinder -   56 Pinion shaft clutch -   58 External tooth system -   60 Disks -   62 Hydraulic cylinder -   A Input-drive shaft axis -   Z Intermediate shaft axis -   H Horizontal axis offset -   V Vertical axis offset -   P Output-drive shaft axis -   α Output-drive shaft axis angle -   ω_(1,2,3) Rotation speed 

1. A marine-vessel transmission having (a) an input-drive shaft (10), which extends along an input-drive shaft axis (A) and on which an input-drive shaft gearwheel (12) is arranged, (b) a first pinion shaft (14), which extends coaxially with respect to the input-drive shaft (10) and on which a first pinion (16) is arranged, (c) a second pinion shaft (24), which extends parallel to the input-drive shaft (10) and on which a pinion shaft gearwheel (28), which engages with the input-drive shaft gearwheel (12), and a second pinion (26) are arranged, (d) an intermediate shaft (18), on which a spur gear (20), which engages with the first pinion (16) and the second pinion (26), and a bevel pinion (22) are arranged, and (e) an output-drive shaft (30), which extends along an output-drive shaft axis (P) which runs at an angle (α) of more than 75° with respect to the input-drive shaft axis (A), and on which a spur bevel gear (31) is arranged, which forms a bevel drive with the bevel pinion (22).
 2. The marine-vessel transmission as claimed in claim 1, wherein the input-drive shaft has a shaft stub (11) for connection to an engine, and the spur bevel gear (31) is arranged on the same side as the shaft stub (11) with respect to a plane through the first pinion (16), the second pinion (26) and the spur gear.
 3. The marine-vessel transmission as claimed in claim 1, wherein a switchable input-drive shaft clutch (50) is arranged on the input-drive shaft (10), by means of which the input-drive shaft gearwheel (12) can be connected to the first pinion shaft (14) such that they rotate together.
 4. The marine-vessel transmission as claimed in claim 3, wherein the input-drive shaft gearwheel (12) is in the form of a housing, which has an external tooth system, of the disk clutch.
 5. The marine-vessel transmission as claimed in claim 1, wherein a switchable pinion shaft clutch (56) is arranged on the second pinion shaft (24), by means of which the pinion shaft gearwheel (28) can be connected to the second pinion shaft (24) such that they rotate together.
 6. The marine-vessel transmission as claimed in claim 5, wherein the switchable pinion shaft clutch (26) is a hydraulically switchable disk clutch.
 7. The marine-vessel transmission as claimed in claim 5, wherein the pinion shaft gearwheel (28) is in the form of a housing, with an external tooth system, of the pinion shaft clutch (56).
 8. The marine-vessel transmission as claimed in claim 5, comprising an electrical drive unit which is designed in order to switch the input-drive shaft clutch (50) and the pinion shaft clutch (56) such that at most one of the two always produces a connection such that they rotate together.
 9. The marine-vessel transmission as claimed in claim 1, comprising a torque tap-off journal for tapping off a torque at a point which is not the same as the output-drive shaft (30).
 10. The marine-vessel transmission as claimed in claim 1, comprising a torque introduction journal for introduction of an input-drive torque.
 11. The marine-vessel transmission as claimed in claim 1, wherein the input-drive shaft axis (A) runs essentially horizontally when the marine-vessel transmission is in the installed position.
 12. The marine-vessel transmission as claimed in claim 1, wherein the marine-vessel transmission is designed to continuously transmit a mechanical power of more than 430 kW, in particular of more than 1300 kW.
 13. A marine vessel, in particular a yacht, having (a) at least one engine, (b) a marine-vessel transmission (32) as claimed in one of the preceding claims, which is connected to the engine, and (c) a propeller pod, which comprises at least one propeller which is connected to the marine-vessel transmission.
 14. The marine vessel as claimed in claim 13, wherein the propeller has a propeller axis which includes an angle of less than 10° with the input-drive shaft axis (A).
 15. The marine vessel as claimed in claim 13, comprising an electric engine which is connected to a torque introduction journal of the marine-vessel transmission. 